1. Field of the Invention
The present disclosure generally relates to electronic memories, and more particularly, the present invention relates to a flash memory device and to a memory system which includes flash memory.
A claim of priority is made under 35 U.S.C §119 to Korean Patent Application Number 10-2007-0024090 filed on Mar. 12, 2007, the entire contents of which are hereby incorporated by reference.
2. Description of the Related Art
Semiconductor memory devices can generally be divided into two main categories, namely, volatile memory devices and non-volatile memory devices. Volatile memory devices include devices such as, for example, Random Access Memory (RAM), Dynamic Random Access Memory, and other such devices. A salient feature of volatile memory devices is that they loose stored data in the event of a power loss. On the other hand, non-volatile memory devices such as, for example, flash memories retain their stored data even in the event of a power loss.
Because of their ability to store data even in the event of a power loss, flash memories are becoming increasingly popular in the electronics industry. Indeed, flash memories are used in various electronic devices such as, for example, digital cameras and portable music players. Furthermore, due to advances in semiconductor fabrication technology, the storage capacity of flash memories is being constantly increased. Thus, relatively large amounts of data can now be stored in a flash memory device. While the storage capacities of flash memories are being increased, the performance of flash memories may be limited by a number of factors. For example, certain operations need to be performed in a flash memory device that may limit the operating speed, i.e., the speed at which data may be written to and read from the flash memory device. These operations may include a copy-back program operation, a merge operation, and other such operations.
A copy-back program operation includes copying data from one page in the memory to another. A merge operation includes copying data from one memory block to another. Such operations may need ancillary operations such as, for example, generating a command, determining a source address/destination address, determining the data to be copied/merged, etc. In conventional memory devices, these and other such operations are performed by the firmware associated with the memory device. However, the time taken to perform these operations using firmware may be more than the time taken if these operations were to be performed in hardware. Furthermore, the time needed to perform these operations may limit the overall operating speed of the memory device. This problem may be exacerbated as the amount of data stored in the memory device increases. That is, an increase in storage capacity may be accompanied by an increase in the time for performing copy-back, merge, and other such operations using firmware.
There is therefore a need to perform internal operations of a flash memory device using hardware. The present disclosure is directed towards overcoming one or more limitations associated with the conventional flash memory devices.